This application is based upon and claims the benefit of priority from the prior Japanese Patent Application No. 2000-200238, filed Jun. 30, 2000, the entire contents of which are incorporated herein by reference.
The present invention relates to a portable electronic apparatus such as a portable computer or a portable information tool and an extension apparatus for extending the function of the electronic apparatus.
To enhance the commercial value, it is greatly important for electronic apparatuses, such as portable computers, to excel in portability. The portable computers recently developed therefore have a housing that is thinner and lighter than before. They are small and light enough to be put into, for example, bags and to be carried with.
A portable computer is compact, having a thin housing. Hence, it is difficult for the housing to have spaces for accommodating connectors for connecting input/output devices to the computer, a floppy disk drive, and a CD-ROM drive. For this reason, the portable computers recently developed each have a dedicated first extension connector. The first extension connector connects the computer to an extension apparatus called a xe2x80x9cdocking station.xe2x80x9d The function of the portable computer is thereby so extended that the portable computer can perform functions that are comparable with those of desktop computers.
Conventional extension apparatuses have a box-shaped base each. The base has a flat mount section. The mount section has a size that enables the housing of a portable computer to be placed thereon. On the mount section, there is arranged a second extension connector. The second extension connector will be electrically connected to the first extension connector when the housing of the portable computer is mounted on the mount section. The base contains various extension components such as a circuit board, a floppy disk drive, a CD-ROM drive and speakers. The circuit board has a number of circuit parts mounted on it. Various connectors and ports are arranged on the side and back walls of the base. These connectors and ports are provided to connect peripheral devices such as a keyboard, a display and a printer to the computer. The connectors and ports will be electrically connected to the portable computers by the first and second extension connectors when the housing is mounted on the mount section of the base. The logic addresses and control signal paths (e.g., data buses) of the portable computer are electrically connected to those of the extension apparatus. This extends the function of the portable computer.
The portable computers that have been recently developed have an MPU (microporcessor unit) each. The MPU is designed to process useful multimedia information that represents characters, sound, speeches and images. MPUs have been improved to process information at a higher speed and to perform more functions. The faster an MPU processes information and the more functions it performs, the more electric power it will consume. There is the trend that the heat, which the MPU generates while operating, increases in proportion to the power the MPU consumes. To contain an MPU of a high calorific value in the housing of a portable computer, it is necessary to sufficiently enhance the heat radiation performance of the MPU.
In light of this, the conventional portable computers contain, in their housings, a heat sink thermally connected to the MPU, and a fan unit for supplying cooling air to the heat sink, which are used for forcibly cooling the MPU. Further, if the MPU executes a complicated operation, with the portable computer connected to an extension apparatus, it generates much more heat. For this reason, when using the portable computer with an extension apparatus connected thereto, a method for enhancing the heat radiation performance of the MPU by forcibly supplying cooling air into the housing from the extension apparatus has been tested.
Specifically, in the extension apparatus, an air vent is formed in a mount section of its base, and a fan unit is provided in the base for supplying cooling air into the air vent. On the other hand, in the portable computer, a communication hole is formed in the bottom wall of the housing opposing the mount section, and a heat sink is provided in the housing in a position corresponding to the communication hole. In this structure, when the housing of the portable computer is placed on the extension apparatus, the air vent opposes the communication hole. Accordingly, the cooling air flows into the housing through the air vent and the communication hole, and rushes onto the heat sink. As a result, the heat radiation performance of the heat sink is enhanced to thereby maintain the operation temperature of the MPU at an appropriate level.
However, where a communication hole as a cooling air inlet is formed in the bottom wall of the portable computer, the following problem will occur.
If the fan unit contained in the housing operates when using the portable computer with no extension apparatus, air outside the housing is drawn into the housing through the communication hole. This air flow disturbs the cooling air path formed in the housing.
As a result, it is very possible that the flow rate of the cooling air guided to the heat sink will be reduced or heat will be locally accumulated in the housing. This means that when using the portable computer without any extension apparatus, the heat radiation performance of the MPU may be degraded compared to the case where no communication hole is provided. Thus, it is very difficult to design a heat radiation mechanism for enhancing the heat radiation performance of the MPU.
The object of this invention is to provide an electronic apparatus capable of maintaining, at a high level, the heat radiation performance of a heat generating component incorporated therein to thereby maintain the operation temperature of the heat generating component at an appropriate level, irrespective of whether the apparatus is used without any extension apparatus, or the apparatus is used together with an extension apparatus.
To achieve this object, according to a first aspect of the invention, there is provided an electronic apparatus comprising: a housing removably coupled to an extension apparatus, the housing containing a heat generating component and having a communication hole opposing the extension apparatus; a heat sink contained in the housing, and thermally connected to the heat generating component for absorbing and radiating heat of the heat generating component; a lid provided in the housing such that the lid is movable between a first position for closing the communication hole, and a second position for opening the communication hole, the lid being moved to the second position when the housing is connected to the extension apparatus; and urging means always urging the lid toward the first position.
In the above structure, when using the electronic apparatus without any extension apparatus, the lid is shifted to the first position and closes the communication hole. Accordingly, outside air is prevented from flowing into the housing through the communication hole, thereby preventing the flow path of the cooling air in the housing from being changed or disturbed.
When the electronic apparatus is connected to the extension apparatus, the lid shifts from the first position to the second position, thereby opening the communication hole. Although, in this case, the heat generating component generates more heat when executing a complicated operation using the connected extension apparatus, the heat sink exhibits a higher heat radiation performance by virtue of the opened communication hole. Thus, the operation temperature of the heat generating component can be maintained at an appropriate level irrespective of whether or not the electronic apparatus is connected to the extension apparatus.
According to a second aspect of the invention, there is provided an extension apparatus comprising: a main body containing a heat generating component and having an outer wall, the outer wall having a communication hole formed therein; a heat sink contained in the main body, and thermally connected to the heat generating component for absorbing and radiating heat of the heat generating component; a lid having heat conductivity, and provided in the main body such that the lid is movable between a first position for closing the communication hole, and a second position for opening the communication hole, the lid being thermally disconnected from the heat sink when it is in the first position, and thermally connected to the heat sink when it is in the second position; urging means always urging the lid toward the first position; and an extension apparatus on which the main body is removably mounted, the extension apparatus having components for extending a function of the main body, and operation means for shifting the lid from the first position to the second position against an urging force of the urging means, when the main body is mounted on the extension apparatus.
In the above structure, when using the electronic apparatus without any extension apparatus, the lid is shifted to the first position and closes the communication hole. Accordingly, the lid is thermally disconnected from the heat sink, thereby preventing the heat of the heat generating component from being transmitted to the lid. This being so, even when the operator touches the lid while carrying out the electronic apparatus, the lid is not hot to the touch.
Furthermore, since the communication is closed, outside air is prevented from flowing into the housing through the communication hole, thereby preventing the flow path of the cooling air in the housing from being changed or disturbed.
When the electronic apparatus is mounted on the extension apparatus, the lid shifts from the first position to the second position, thereby thermally connecting the lid to the heat sink. As a result, the heat capacity and the heat radiation area of the heat sink are increased by the amount of those of the lid. In addition, when the lid is shifted, the communication hole is opened. The heat sink that receives the heat of the heat generating component can be effectively cooled by cooling air supplied thereto from the extension apparatus through the communication hole. Consequently, even if the heat generating component generates more heat when executing a complicated operation using the connected extension apparatus, the heat sink exhibits a higher heat radiation performance by virtue of the opened communication hole. Thus, the operation temperature of the heat generating component can be maintained at an appropriate level irrespective of whether or not the electronic apparatus is connected to the extension apparatus.
According to a third aspect of the invention, there is provided an extension apparatus to be removably coupled to an electronic apparatus that includes a housing having a communication hole, a lid provided in the housing such that it is movable between a first position for closing the communication hole, and a second position for opening the communication hole, and a heat generating component contained in the housing, comprising: a base on which the housing of the electronic apparatus is removably mounted; components contained in the base for extending a function of the electronic apparatus; operation means for shifting the lid from the first position to the second position when the electronic apparatus is mounted on the base; and blower means contained in the base for blowing cooling air to the communication hole formed in the electronic apparatus placed on the base.
In the above structure, when using the electronic apparatus without any extension apparatus, the lid closes the communication hole. Accordingly, outside air is prevented from flowing into the housing through the communication hole, thereby preventing the flow path of the cooling air in the housing from being changed or disturbed.
When the electronic apparatus is mounted on the extension apparatus, the lid shifts from the first position to the second position, thereby opening the communication hole. When the blower means is operated, cooling air is guided into the housing of the electronic apparatus through the communication hole. Thus, the ventilation in the housing is enhanced and the amount of air applied to the heat sink is increased. Consequently, even if the heat generating component generates more heat when executing a complicated operation using the connected extension apparatus, the heat sink exhibits a higher heat radiation performance by virtue of the opened communication hole. Thus, the operation temperature of the heat generating component can be maintained at an appropriate level irrespective of whether or not the electronic apparatus is connected to the extension apparatus.
According to a fourth aspect of the invention, there is provided an electronic apparatus system comprising: an electronic apparatus having a housing, a heat generating component provided in the housing, and a heat sink thermally connected to the heat generating component; and an extension apparatus having a base on which the housing of the electronic apparatus is removably mounted, and components provided in the base for extending a function of the electronic apparatus, wherein the housing of the electronic apparatus has a communication hole opposing the base, and a lid having heat conductivity and provided in the housing such that the lid is movable between a first position for closing the communication hole, and a second position for opening the communication hole, the lid being thermally disconnected from the heat sink when it is in the first position, and thermally connected to the heat sink when it is in the second position; and the extension apparatus has operation means for shifting the lid from the first position to the second position when the housing of the electronic apparatus is mounted on the base, and also has blower means for blowing cooling air into the communication hole.
In the above structure, when using the electronic apparatus without any extension apparatus, the lid is shifted to the first position and closes the communication hole. Accordingly, the lid is thermally disconnected from the heat sink, thereby preventing the heat of the heat generating component from being transmitted to the lid. This being so, even when the operator touches the lid while carrying out the electronic apparatus, the lid is not hot to the touch.
Furthermore, since the communication is closed, outside air is prevented from flowing into the housing through the communication hole, thereby preventing the flow path of the cooling air in the housing from being changed or disturbed.
When the electronic apparatus is mounted on the extension apparatus, the lid shifts from the first position to the second position, thereby thermally connecting the lid to the heat sink. As a result, the heat capacity and the heat radiation area of the heat sink are increased by the amounts of those of the lid. In addition, when the lid is shifted, the communication hole is opened. Through the opened communication hole, cooling air is supplied into the housing by the blower means, thereby enhancing the ventilation in the housing and increasing the amount of cooling air directed to the heat sink. Consequently, even if the heat generating component generates more heat when executing a complicated operation using the connected extension apparatus, the heat sink shows a higher heat radiation performance by virtue of the opened communication hole. Thus, the operation temperature of the heat generating component can be maintained at an appropriate level irrespective of whether or not the electronic apparatus is connected to the extension apparatus.
Additional objects and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and obtained by means of the instrumentalities and combinations particularly pointed out hereinafter.